The invention relates to a scavenging apparatus for embedding cables or the like into the soil of waters.
Cables and other lines are laid for Protection reasons into the soil of waters. If the soil consists of a scavengeable formation, a slot or a trench is drawn in the soil with the assistance of a scavenging apparatus and simultaneously, the cable is laid into the trench. Such an apparatus is known for instance from the U.S. Pat. No. 3,434,297. The scavenging apparatus has a scavenging sword pivotally attached to a vessel which can be driven on the soil of waters. The scavenging sword has a guide channel for the cable and a water channel which is connected to scavenging nozzles. The scavenging nozzles are directed to the front side of the scavenging sword and scavenge free the soil area into which afterwards the cable is laid.
From DE-OS 1 484 692 it is also known to provide teeth on the front side of such a scavenging sword serving for a mechanical loosening of the soil material to be scavenged. From the above mentioned Publication and from DE-PS 29 22 410, it is also known to connect a vibrator to the scavenging sword. The vibrator puts the scavenging sword into vibration motions by which an additional mechanical loosening of the soil takes place. In the known scavenging apparatuses, the vibrator is located on the upper side of the scavenging sword. In scavenging swords attached to a surface water vessel, the upper end of the scavenging sword and hence the vibrator are above the water surface.
The object of the invention is to provide a scavenging apparatus with such a vibration arrangement that the vibration energy is efficiently converted.
This object is attached by the invention.
In the scavenging apparatus according to the invention, the vibrator is located within the scavenging sword near the sole of the sword. The energy supply lines are extended within the scavenging sword, above all due to protection reasons.
The position of the vibrator according to the invention in the rear area of the scavenging sword effects that the vibration energy is produced at a point where it is needed, that is in the region of the scavenging sword getting into contact with the underground. Further, the vibration direction can be chosen to be an optimum for the soil loosening.
Advantageously, the vibrator is hydraulically driven. The energy supply lines, for instance the hydraulic lines, extend to the lower region within the scavenging sword, advantageously in a separate channel. The vibrator itself can be waterproof encased, thus, having a sealed casing for its own. However, a necessity does not exist therefor.
The vibrator naturally has a definite switch. In an embodiment of the invention, the scavenging sword has an enlargement near the sole wherein the vibrator is placed. The enlargement, however, is uncritical, particularly if it extends only gradually to its complete width in the direction away from the front side of the scavenging sword.
The guide channel for the cable is in the rearward area of the scavenging sword (when above and in the following "in front" and "behind" is mentioned the orientation of the sides of the scavenging sword is meant resulting from the forward movement). According to an embodiment of the invention, a second water channel is located near the rear edge of the scavenging sword limiting the guide channel and connected to nozzles which are directed towards the guide channel. The nozzles spray water under pressure into the guide channel and thus facilitate the forward movement of the cable in the guide channel, above all, by reducing the friction on the guide channel wall.
The invention is explained in detail in the following along accompanied drawings.